Vacuum cleaners generally include a suction conduit with an opening on the underside of a surface cleaning head for drawing air (and debris) into and through the surface cleaning head. One of the challenges with vacuum cleaner design is to control engagement of the suction conduit with a surface being cleaned to provide the desired amount of suction. If the suction conduit is spaced too far from a surface, the suction may be less because the air is flowing into the suction conduit through a greater surface area. If the suction conduit is directly engaged with the surface and thus sealed on all sides, air will stop flowing into the suction conduit and the suction motor may be damaged as a result.
Vacuum cleaners also generally use agitation to loosen debris and facilitate capturing the debris in the flow of air into the suction conduit. Agitators are often used in the suction conduit of a surface cleaning head proximate a dirty air inlet to cause the agitated debris to flow into the dirty air inlet. If the agitator in the suction conduit is unable to loosen the debris or if the debris is too small, the suction conduit may pass over the debris without removing the debris from the surface. In other cases, the surface cleaning head may push larger debris forward without ever allowing the debris to be captured in the flow into the suction conduit (sometimes referred to as snowplowing). A rotating agitator may also cause the debris to circulate without being captured in the air flow into the dirty air inlet.
One example of an agitator is a cleaning roller such as a brush roll. A cleaning roller may be located within a suction conduit and/or may be located at a leading side of a suction conduit (e.g., a leading roller). One challenge with cleaning rollers is the ability to access the cleaning rollers, for example, to remove debris and/or replace the cleaning rollers. Other challenges include accommodating two cleaning rollers within the housing and driving the two cleaning rollers.